var username = document.getElemenetElementById("upsd").value;
	var erro1 = document.getElementById("erro1");	
	var erro2 = document.getElementById("erro2");
function cheak(){
		if(uname==''||uname==null){
			erro1.innerHTML="请输入用户名"
		}
		if(upsd==''||upsd==null){
			erro2.innerHTML="请输入密码"
		}

}
function change(){
	document.getElementById("register_main").style.zIndex=2;
	document.getElementById("form1").style.zIndex=1;
}
function rechange(){
	document.getElementById("register_main").style.zIndex=1;	
	document.getElementById("form1").style.zIndex=2;
}
